Binding structure, ultrasonic fingerprint identification module and electronic equipment
By introducing a conductive structure and a passivation layer between the flexible circuit board and the silicon substrate, the shortcomings in the connection stability and conductivity between the flexible circuit board and the silicon substrate are solved, achieving higher mechanical strength and electrical reliability, making it suitable for full-screen devices and embedded applications.
Patent Information
- Application Number
- CN202522264036.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-27
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2035-10-27
AI Technical Summary
Traditional bonding methods have certain limitations in terms of reliability, space utilization, and manufacturing process. In particular, the stability and conductivity of the connection between the flexible circuit board and the silicon substrate layer are difficult to meet the current requirements of high-density integration.
The invention employs a silicon substrate, a flexible circuit board, a passivation layer, and a conductive structure. An electrical connection between the flexible circuit board and the silicon substrate is achieved through a window structure on the silicon substrate. An electrical connection between the silicon substrate and the conductive structure is achieved through the conductive structure. An electrical connection between the first interconnect layer and the second interconnect layer is achieved through the conductive structure.
This improves the connection stability and conductivity between the flexible circuit board and the silicon substrate, enhances the mechanical strength and conductive reliability of the bonding structure, reduces installation space requirements, and improves assembly efficiency and product yield.
Smart Images
Figure CN223679673U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to integrated circuit technical field, especially relate to a kind of binding structure, ultrasonic fingerprint identification module and electronic equipment. BACKGROUND
[0002] With the continuous development of electronic equipment and the demand of user for operation convenience and security, fingerprint identification technology has been widely applied in various electronic products. Among them, ultrasonic fingerprint identification technology is concerned due to its unique physical characteristics. The technology uses the ability of ultrasonic wave to penetrate different materials, and obtains fingerprint feature information according to the echo signal difference, with high precision and security. Since ultrasonic fingerprint identification technology can penetrate glass, metal (such as aluminum, stainless steel) and sapphire and other materials for identification, it shows great application potential in full screen devices or embedded design. However, with the development of electronic equipment towards thin and full screen, fingerprint identification module needs to be more ingeniously integrated under the screen or other limited space, which puts higher requirements on the overall structure design of ultrasonic fingerprint identification module. The traditional binding method has certain limitations in reliability, space utilization and manufacturing process, and it is difficult to fully meet the current high-density integration requirements. Especially when using the technical scheme of flexible circuit board (FPC) and chip binding, how to ensure the stability and conductivity of the connection between FPC and chip becomes a technical problem to be solved at present. UTILITY MODEL CONTENT
[0003] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the utility model is to provide a binding structure, ultrasonic fingerprint identification module and electronic equipment for improving the stability and conductivity of the connection between FPC and chip.
[0004] The above-mentioned purpose of the utility model can be realized by using the following technical scheme. The utility model provides a binding structure, which comprises:
[0005] Silicon substrate layer, the first interconnection layer is arranged on the silicon substrate layer;
[0006] Flexible circuit board, the second interconnection layer is arranged on the flexible circuit board;
[0007] Passivation layer, the passivation layer is arranged on the silicon substrate layer and covers the first interconnection layer, and the window structure is arranged on the passivation layer;
[0008] Conductive structure, the conductive structure comprises adhesive layer and conductive layer, at least part of the adhesive layer is arranged on the first interconnection layer in the window structure, the conductive layer is arranged on the adhesive layer, and the conductive layer is used for electrically connecting the second interconnection layer.
[0009] In a preferred embodiment of the present application, the first interconnection layer comprises a metal pad disposed on the silicon substrate layer.
[0010] In a preferred embodiment of the present application, the metal pad is an aluminum pad.
[0011] In a preferred embodiment of the present application, the second interconnection layer comprises an ACF layer disposed on the flexible circuit board.
[0012] In a preferred embodiment of the present application, the conductive structure comprises the adhesion layer formed by evaporation and a conductive layer formed by evaporation on the adhesion layer, and the conductive layer is electrically connected to the second interconnection layer.
[0013] In a preferred embodiment of the present application, the material of the adhesion layer is Ti, and the thickness of the adhesion layer is ≤0.2um.
[0014] In a preferred embodiment of the present application, the material of the conductive layer is Au, and the thickness of the conductive layer is ≥1.5um.
[0015] In a preferred embodiment of the present application, the material of the conductive layer is Ag, and the thickness of the conductive layer is ≥1.5um.
[0016] In a preferred embodiment of the present application, the material of the conductive layer is Cu, and the thickness of the conductive layer is ≥0.1um.
[0017] In a preferred embodiment of the present application, the conductive structure further comprises a first hard layer formed by evaporation on the conductive layer, and the first hard layer is electrically connected to the second interconnection layer.
[0018] In a preferred embodiment of the present application, the material of the first hard layer is one of Ni or NiAu.
[0019] In a preferred embodiment of the present application, the thickness of the first hard layer is ≥0.1um.
[0020] In a preferred embodiment of the present application, the conductive structure further comprises a second hard layer formed by evaporation on the adhesion layer, and the conductive layer is formed by evaporation on the second hard layer.
[0021] In a preferred embodiment of the present application, the material of the second hard layer is one of Ni or NiAu.
[0022] In a preferred embodiment of the present application, the thickness of the second hard layer is 0.1um to 0.2um.
[0023] In a preferred embodiment of the utility model, the conductive structure further includes a third hard layer which is evaporated and formed on the conductive layer, and the third hard layer is electrically connected to the second interconnection layer.
[0024] In a preferred embodiment of the utility model, the material of the third hard layer is one of Ni or NiAu.
[0025] In a preferred embodiment of the utility model, the thickness of the third hard layer is greater than or equal to 0.1 um.
[0026] In a preferred embodiment of the utility model, the conductive structure includes the adhesion layer which is sputtered and formed, the seed layer which is sputtered and formed on the adhesion layer, and the conductive layer which is electroplated on the seed layer, and the conductive layer is electrically connected to the second interconnection layer.
[0027] In a preferred embodiment of the utility model, the material of the adhesion layer is Ti, and the thickness of the adhesion layer is less than or equal to 0.2 um.
[0028] In a preferred embodiment of the utility model, the material of the seed layer is TiW, and the thickness of the seed layer is less than or equal to 0.5 um.
[0029] In a preferred embodiment of the utility model, the material of the conductive layer is Au, and the thickness of the conductive layer is greater than or equal to 1.5 um.
[0030] In a preferred embodiment of the utility model, the conductive structure includes the adhesion layer which is sputtered and formed, the seed layer which is sputtered and formed on the adhesion layer, the conductive layer which is electroplated on the seed layer, and the fourth hard layer which is electroplated on the conductive layer, and the fourth hard layer is electrically connected to the second interconnection layer.
[0031] In a preferred embodiment of the utility model, the material of the adhesion layer is Ti, and the thickness of the adhesion layer is less than or equal to 0.2 um.
[0032] In a preferred embodiment of the utility model, the material of the seed layer is Cu, and the thickness of the seed layer is 0.2 um to 0.4 um.
[0033] In a preferred embodiment of the utility model, the material of the conductive layer is Cu, and the thickness of the conductive layer is greater than or equal to 1.5 um.
[0034] In a preferred embodiment of the utility model, the material of the fourth hard layer is one of Ni or NiAu.
[0035] In a preferred embodiment of the utility model, the thickness of the fourth hard layer is greater than or equal to 0.1 um.
[0036] In a preferred embodiment of the present application, the area of the first interconnection layer is 8000um 2 to 50000um 2 .
[0037] In a preferred embodiment of the present application, the area ratio of the first interconnection layer to the window structure is 1.05 to 1.2.
[0038] In a preferred embodiment of the present application, the first interconnection layer is configured as a rectangle, the width of the first interconnection layer is greater than or equal to 0.04um, and the length of the first interconnection layer is greater than or equal to 0.2um.
[0039] In a preferred embodiment of the present application, the window structure comprises a first window opening which is proportionally reduced relative to the first interconnection layer.
[0040] In a preferred embodiment of the present application, the window structure comprises a plurality of second window openings arranged at intervals.
[0041] In a preferred embodiment of the present application, the projection shape of the second window opening in the thickness direction of the first interconnection layer is a circle, and the diameter of the second window opening is greater than or equal to 25um; or, the projection shape of the second window opening in the thickness direction of the first interconnection layer is a regular polygon, and the diameter of the circumscribed circle of the second window opening is greater than or equal to 25um.
[0042] In a preferred embodiment of the present application, the minimum spacing between the window structure and the edge of the first interconnection layer is greater than or equal to 0.4um.
[0043] The present application also provides an ultrasonic fingerprint identification module comprising the binding structure described above.
[0044] The present application also provides an electronic device comprising the ultrasonic fingerprint identification module described above.
[0045] The technical solution of the present application has the following remarkable advantages:
[0046] The binding structure of the present application can expose part of the first interconnection layer through the window structure on the passivation layer to form a bump area, and can realize electrical connection between the bump area of the first interconnection layer and the second interconnection layer through the conductive structure, thereby forming a stable and efficient electrical connection structure. By covering the passivation layer on the first interconnection layer, the passivation layer not only plays an insulating role, but also further improves the structural stability of the first interconnection layer, so that the first interconnection layer and the conductive structure have better electrical connection stability, thereby ensuring the stability and conductivity of the connection between the flexible circuit board and the silicon substrate layer.
[0047] And, the interface adhesion performance is enhanced through the adhesion layer, the connection stability of the conductive layer is improved, the interlayer peeling or contact failure caused by external force or thermal stress is prevented, and thus the overall mechanical strength and conductive reliability of the binding structure are significantly improved. Moreover, the first interconnection layer, the passivation layer, the conductive structure and the second interconnection layer are integrally arranged in a stacked manner and can be arranged in a gap between the flexible circuit board and the silicon substrate layer, have better integration, and are beneficial to reducing the required installation space.
[0048] The binding structure can better meet the binding requirements between the flexible circuit board and the silicon substrate layer, and has the advantages of ensuring electrical performance and considering the stability of mechanical connection, and particularly plays an important role in improving assembly efficiency, reducing manufacturing cost and improving product yield in full-screen equipment or embedded applications. BRIEF DESCRIPTION OF DRAWINGS
[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.
[0050] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present application in any way. In addition, the shapes and scale sizes of the components in the drawings are only illustrative and are used to help understand the present application, and are not specific limitations on the shapes and scale sizes of the components of the present application. Those skilled in the art can select various possible shapes and scale sizes to implement the present application according to specific conditions under the guidance of the present application.
[0051] Figure 1 Structure schematic view of a first embodiment of the binding structure of the present application;
[0052] Figure 2 Structure schematic view of a second embodiment of the binding structure of the present application;
[0053] Figure 3 Structure schematic view of a third embodiment of the binding structure of the present application;
[0054] Figure 4 Structure schematic view of a fourth embodiment of the binding structure of the present application;
[0055] Figure 5 Structure schematic view of a fifth embodiment of the binding structure of the present application;
[0056] Figure 6Structure diagram of the first embodiment of the window structure of the utility model;
[0057] Figure 7 Structure diagram of the second embodiment of the window structure of the utility model;
[0058] Figure 8 Structure diagram of the third embodiment of the window structure of the utility model;
[0059] Figure 9 Structure diagram of the fourth embodiment of the window structure of the utility model.
[0060] Reference signs of the above drawings:
[0061] 100, silicon substrate layer; 110, first interconnection layer; 111, metal pad;
[0062] 200, flexible circuit board; 210, second interconnection layer;
[0063] 300, passivation layer; 310, window structure; 311, first window; 312, second window;
[0064] 400, conductive structure; 410, adhesive layer; 420, conductive layer; 430, first hard layer; 440, second hard layer; 450, third hard layer; 460, seed layer; 470, fourth hard layer. DETAILED DESCRIPTION
[0065] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.
[0066] Embodiment one
[0067] Please refer to Figures 1 to 9As shown, the embodiment of the utility model provides a kind of binding structure, which includes silicon substrate layer 100, flexible circuit board 200, passivation layer 300 and conductive structure 400, and the first interconnection layer 110 is equipped on silicon substrate layer 100;Flexible circuit board 200 is equipped with the second interconnection layer 210;Passivation layer 300 is arranged on silicon substrate layer 100 and covers the first interconnection layer 110, and window structure 310 is equipped on passivation layer 300;Conductive structure 400 includes adhesive layer 410 and conductive layer 420, at least part of adhesive layer 410 is arranged on the first interconnection layer 110 in window structure 310, and conductive layer 420 is arranged on adhesive layer 410, and conductive layer 420 is used to electrically connect the second interconnection layer 210.
[0068] The binding structure can expose part of the first interconnection layer 110 through the window structure 310 on the passivation layer 300 to form a bump area, and can realize electrical connection between the bump area of the first interconnection layer 110 and the second interconnection layer 210 through the conductive structure 400, thereby forming a stable and efficient electrical connection structure.
[0069] By covering the passivation layer 300 on the first interconnection layer 110, the passivation layer 300 not only plays an insulating role, but also further improves the structural stability of the first interconnection layer 110, so that the first interconnection layer 110 and the conductive structure 400 have better electrical connection stability, thereby ensuring the stability and conductivity of the connection between the flexible circuit board 200 and the silicon substrate layer 100.
[0070] Moreover, the interface adhesion performance is enhanced by the adhesive layer 410, the connection stability of the conductive layer 420 is improved, and interlayer peeling or contact failure caused by external force or thermal stress is prevented, thereby significantly improving the overall mechanical strength and conductive reliability of the binding structure. Moreover, the first interconnection layer 110, the passivation layer 300, the conductive structure 400 and the second interconnection layer 210 are integrally arranged, and can be placed in the gap between the flexible circuit board 200 and the silicon substrate layer 100, have better integration, and are beneficial to reducing the required installation space.
[0071] The binding structure can better meet the binding requirements between the flexible circuit board 200 and the silicon substrate layer 100, and can ensure electrical performance while considering the stability of mechanical connection, especially in full-screen devices or embedded applications, which plays an important role in improving assembly efficiency, reducing manufacturing cost and improving product yield.
[0072] In the embodiment of the utility model, first interconnection layer 110 includes metal pad 111 set on silicon substrate layer 100. Among them, metal pad 111 has excellent conductivity and thermal stability, thereby can provide reliable connection basis for conductive structure 400, strengthens the overall electrical performance and mechanical strength of binding structure.
[0073] Design personnel can adjust the setting quantity and specific material of metal pad 111 according to the need of use, not specifically limited here. Preferably, metal pad 111 is aluminum pad. Design personnel can adjust the setting quantity and arrangement mode of aluminum pad according to the need of use, not specifically limited here. In a feasible embodiment, aluminum pad is provided with one. In another feasible embodiment, aluminum pad is provided with multiple, and multiple aluminum pads are arranged with layer spacing.
[0074] Among them, aluminum pad has excellent conductivity, processability, and good compatibility between aluminum pad and silicon substrate layer 100, can effectively reduce contact resistance and improve signal transmission efficiency.
[0075] In the embodiment of the utility model, second interconnection layer 210 includes ACF layer set on flexible circuit board 200. Specifically, ACF layer is composed of anisotropic conductive material, effectively realizes the dual functions of signal transmission and electrical isolation, and ACF layer also has excellent adhesive performance, which helps to improve the stability of electrical connection.
[0076] In the first feasible embodiment of the utility model, as shown in the embodiment shown in the figure, Figure 1 Conductive structure 400 includes adhesion layer 410 formed by evaporation and conductive layer 420 formed by evaporation on adhesion layer 410, and conductive layer 420 is electrically connected with second interconnection layer 210.
[0077] Adhesion layer 410 and conductive layer 420 formed by evaporation process realize the electrical connection between first interconnection layer 110 and second interconnection layer 210, and high-precision, more uniform thin film deposition can be realized by evaporation process, the interface adhesion performance of adhesion layer 410 is enhanced, the bonding strength is effectively improved, so that the structural stability of conductive structure 400 is ensured.
[0078] And, the conductive layer 420 formed by evaporation has excellent conductivity and compactness, can significantly reduce resistance, improve signal transmission efficiency, and can form reliable electrical connection with the second interconnection layer 210, further enhance the overall electrical performance and mechanical reliability of the binding structure.
[0079] In the first feasible embodiment of the utility model, design personnel can adjust the specific material and thickness of adhesion layer 410 according to the need of use, not specifically limited here.
[0080] In an embodiment, the material of the adhesion layer 410 is Ti, and the thickness of the adhesion layer 410 is less than or equal to 0.2 um. Preferably, the thickness of the adhesion layer 410 is 0.1 um.
[0081] By setting the material of the adhesion layer 410 as Ti, titanium has excellent interface adhesion performance and chemical stability, which can effectively prevent peeling or cracking problems caused by the difference in thermal expansion coefficient while ensuring good bonding force. In addition, titanium also has good electrical conductivity and corrosion resistance, which helps to improve the overall electrical stability and durability of the conductive structure 400.
[0082] In addition, by controlling the thickness of the adhesion layer 410 to be less than or equal to 0.2 um, the problem of material accumulation and surface unevenness can be avoided while achieving high-performance adhesion function, which helps to reduce the size of the binding structure and improve the integration of the binding structure.
[0083] In the first feasible implementation manner of the utility model, the designer can adjust the specific material and thickness of the conductive layer 420 according to the use requirement, which is not limited here.
[0084] In an embodiment, the material of the conductive layer 420 is Au, and the thickness of the conductive layer 420 is greater than or equal to 1.5 um. By setting the material of the conductive layer 420 as gold (Au), Au has high hardness and excellent oxidation resistance, which can effectively improve the mechanical strength and wear resistance of the binding position without the need for additional hard layer, prevent poor contact caused by oxidation, and ensure the long-term stability of the conductive layer 420 in complex environments.
[0085] In addition, by making the thickness of the conductive layer 420 greater than or equal to 1.5 um, the surface resistance can be further reduced, the electrical conductivity can be improved, and the protection of the underlying structure can be enhanced, thereby significantly improving the overall reliability and durability of the conductive structure 400.
[0086] In the second feasible implementation manner of the utility model, as shown in the embodiment of Figure 2 The material of the conductive layer 420 is Cu, and the thickness of the conductive layer 420 is greater than or equal to 0.1 um. Preferably, the material of the conductive layer 420 is Cu, and the thickness of the conductive layer 420 is greater than or equal to 1.5 um.
[0087] By setting the material of the conductive layer 420 as copper (Cu), copper has high hardness, excellent electrical conductivity and thermal conductivity, which can significantly reduce the contact resistance, improve the efficiency of electrical signal transmission, and effectively disperse the heat accumulation during work to prevent performance degradation caused by local overheating.
[0088] And, by making the thickness of the conductive layer 420 >= 1.5um, the conductive layer 420 can be ensured to have good continuity and structural density, avoiding the problem of open circuit or unstable resistance caused by being too thin, and helping to enhance the mechanical strength and fatigue resistance of the conductive structure 400.
[0089] In the second feasible embodiment of the utility model, the conductive structure 400 further comprises a first hard layer 430 formed on the conductive layer 420 by evaporation, and the first hard layer 430 is electrically connected to the second interconnection layer 210.
[0090] The first hard layer 430 formed on the conductive layer 420 by evaporation can be electrically connected to the second interconnection layer 210, and the first hard layer 430 further enhances the mechanical strength of the conductive layer 420, improves the hardness at the binding position, and thus reduces the risk of deformation or damage of the binding area caused by external force.
[0091] The designer can adjust the specific material of the first hard layer 430 according to the use requirement, which is not specifically limited herein. In an embodiment, the material of the first hard layer 430 is Ni. In another embodiment, the material of the first hard layer 430 is NiAu.
[0092] By using Ni (nickel) or NiAu (nickel-gold alloy) as the material of the first hard layer 430, the mechanical strength, wear resistance and hardness of the first hard layer 430 are significantly improved, and the first hard layer 430 has better corrosion resistance and oxidation resistance.
[0093] And, by setting the material of the first hard layer 430 as Ni or NiAu, the first hard layer 430 has good electrical conductivity and chemical stability, which can further optimize the current conduction path, reduce the contact resistance, and prevent the influence of Cu oxidation on the connection performance, thereby improving the reliability and durability of the overall conductive structure 400.
[0094] In the second feasible embodiment of the utility model, the designer can adjust the specific thickness of the first hard layer 430 according to the use requirement, which is not specifically limited herein. Preferably, the thickness of the first hard layer 430 is >= 0.1um.
[0095] By making the thickness of the first hard layer 430 >= 0.1um, the mechanical strength and hardness of the first hard layer 430 in the conductive structure 400 can reach the preset target, effectively enhancing the stability and external force deformation resistance of the binding area.
[0096] In the third feasible embodiment of the utility model, the material of the conductive layer 420 is Ag, and the thickness of the conductive layer 420 is >= 1.5um.
[0097] By setting the material of the conductive layer 420 to silver (Ag), which has excellent conductivity and good thermal stability, the contact resistance can be significantly reduced, the electrical signal transmission efficiency can be improved, and the physical properties can be maintained at high temperature.
[0098] Furthermore, by making the thickness of the conductive layer 420 ≥ 1.5 μm, the density and continuity of the conductive layer 420 are enhanced, effectively preventing open circuits or resistance fluctuations caused by the conductive layer 420 being too thin, and improving the mechanical strength and fatigue resistance of the overall structure, ensuring the long-term reliability and stability of the conductive structure 400 in complex application scenarios.
[0099] In the third feasible embodiment of this utility model, such as Figure 3 In the embodiment shown, the conductive structure 400 further includes a second hard layer 440 vapor-deposited on the adhesion layer 410, and the conductive layer 420 vapor-deposited on the second hard layer 440.
[0100] The second hard layer 440 is formed on the adhesion layer 410 by vapor deposition. The second hard layer 440 can be electrically connected to the first interconnect layer 110. The second hard layer 440 further enhances the mechanical strength of the conductive layer 420 and increases the hardness at the bonding location, thereby reducing the risk of deformation or damage to the bonding area caused by external forces.
[0101] Designers can adjust the specific material of the second hard layer 440 according to usage requirements, and no specific limitations are imposed here. In one feasible embodiment, the material of the second hard layer 440 is Ni. In another feasible embodiment, the material of the second hard layer 440 is NiAu.
[0102] By using Ni or NiAu (nickel-gold alloy) as the material for the second hard layer 440, the mechanical strength, wear resistance and hardness of the conductive layer 420 are significantly improved, and it also has better corrosion resistance and oxidation resistance.
[0103] Furthermore, by setting the material of the second hard layer 440 to Ni or NiAu, the second hard layer 440 has good conductivity and chemical stability, which can further optimize the current conduction path, reduce contact resistance, and prevent Ag oxidation from affecting the connection performance, thereby improving the overall reliability and durability of the conductive structure 400.
[0104] In a third feasible embodiment of this utility model, the designer can adjust the specific thickness of the second hard layer 440 according to the usage requirements, and no specific limitation is made here. Preferably, the thickness of the second hard layer 440 is 0.1um to 0.2um.
[0105] By setting the thickness of the second hard layer 440 in the range of 0.1um to 0.2um, the mechanical strength, hardness and electrical conductivity of the second hard layer 440 can be effectively balanced, so that the second hard layer 440 has excellent wear resistance, deformation resistance and current conduction efficiency.
[0106] In the third feasible implementation manner of the utility model, the conductive structure 400 further comprises a third hard layer 450 formed on the conductive layer 420 by evaporation, and the third hard layer 440 is electrically connected to the second interconnection layer 210.
[0107] The third hard layer 450 formed on the conductive layer 420 by evaporation can be electrically connected to the second interconnection layer 210, and the third hard layer 450 further enhances the mechanical strength and wear resistance of the conductive layer 420, improves the hardness of the binding position, and thus reduces the risk of deformation or damage of the binding area caused by external force.
[0108] Specifically, the second hard layer 440, the conductive layer 420 (Ag) and the third hard layer 450 form a sandwich structure, and the second hard layer 440 and the third hard layer 450 can protect the intermediate conductive layer 420, effectively solve the technical problem that the flexible circuit board 200 is prone to deformation or poor contact during the binding process due to the low hardness of the Ag material, and enhance the overall stability and reliability of the binding structure, so as to better meet the dual requirements of conductive performance and structural strength of high-precision electronic devices.
[0109] The designer can adjust the specific material of the third hard layer 450 according to the use requirement, which is not specifically limited here. In an embodiment, the material of the third hard layer 450 is Ni. In another embodiment, the material of the third hard layer 450 is NiAu.
[0110] By using Ni (nickel) or NiAu (nickel-gold alloy) as the material of the third hard layer 450, the mechanical strength and hardness of the third hard layer 450 are significantly improved, and the third hard layer 450 has better corrosion resistance and oxidation resistance.
[0111] In addition, by setting the material of the third hard layer 450 as Ni or NiAu, the third hard layer 450 has good electrical conductivity and chemical stability, which can further optimize the current conduction path, reduce the contact resistance, and prevent the influence of Ag oxidation on the connection performance, thereby improving the reliability and durability of the overall conductive structure 400.
[0112] In the third feasible implementation manner of the utility model, the designer can adjust the specific thickness of the third hard layer 450 according to the use requirement, which is not specifically limited here. Preferably, the thickness of the third hard layer 450 is greater than or equal to 0.1um.
[0113] By setting the thickness of the third hard layer 450 to be greater than or equal to 0.1 um, the mechanical strength and hardness of the third hard layer 450 in the conductive structure 400 can be ensured to reach a preset target, and the stability and anti-external force deformation capability of the binding area are effectively enhanced.
[0114] In the fourth feasible implementation manner of the utility model, as shown in the embodiment, Figure 4 The conductive structure 400 includes an adhesion layer 410 formed by sputtering, a seed layer 460 formed on the adhesion layer 410 by sputtering, and a conductive layer 420 formed on the seed layer 460 by electroplating, and the conductive layer 420 is electrically connected to the second interconnection layer 210.
[0115] By using the sputtering forming process to prepare the adhesion layer 410 and the seed layer 460, the bonding force and interface stability between the adhesion layer 410 and the seed layer 460 can be significantly improved, and the conductive layer 420 formed by subsequent electroplating has good adhesion and uniformity.
[0116] Moreover, the adhesion layer 410 formed by sputtering, the seed layer 460, and the conductive layer 420 formed by electroplating cooperate with each other, not only enhancing the mechanical bonding strength between the adhesion layer 410, the seed layer 460, and the conductive layer 420, but also effectively reducing the interface contact resistance and optimizing the current conduction performance.
[0117] In the fourth feasible implementation manner of the utility model, the designer can adjust the specific material and thickness of the adhesion layer 410 according to the use requirement, which is not specifically limited here.
[0118] In an embodiment, the material of the adhesion layer 410 is Ti, and the thickness of the adhesion layer 410 is less than or equal to 0.2 um. Preferably, the thickness of the adhesion layer 410 is 0.1 um.
[0119] In the fourth feasible implementation manner of the utility model, the designer can adjust the specific material and thickness of the seed layer 460 according to the use requirement, which is not specifically limited here. In an embodiment, the material of the seed layer 460 is TiW, and the thickness of the seed layer 460 is less than or equal to 0.5 um.
[0120] By setting the material of the seed layer 460 to be TiW (titanium tungsten alloy) and controlling the thickness of the seed layer 460 to be less than or equal to 0.5 um, the interface bonding force between the seed layer 460 and the adhesion layer 410 can be effectively improved, while good electrical conductivity and thermal stability are ensured. Not only the adhesion performance and uniformity of the subsequent electroplated conductive layer 420 are enhanced, but also the interface contact resistance is significantly reduced, thereby optimizing the current conduction efficiency.
[0121] In the fourth feasible implementation mode of the utility model, the designer can adjust the specific material and thickness size of the conductive layer 420 according to the use requirement, which is not specifically limited here. In a feasible embodiment, the material of the conductive layer 420 is Au, and the thickness of the conductive layer 420 is greater than or equal to 1.5 um.
[0122] In the fifth feasible implementation mode of the utility model, as shown in the embodiment, Figure 5 The conductive structure 400 includes the sputtering-formed adhesion layer 410, the seed layer 460 sputtering-formed on the adhesion layer 410, the conductive layer 420 electroplated on the seed layer 460, and the fourth hard layer 470 electroplated on the conductive layer 420, and the fourth hard layer 470 is electrically connected to the second interconnection layer 210.
[0123] By adopting the sputtering process to prepare the adhesion layer 410 and the seed layer 460, the bonding force and interface stability between the adhesion layer 410 and the seed layer 460 can be significantly enhanced, and the conductive layer 420 formed by subsequent electroplating has good adhesion and uniformity.
[0124] Moreover, by electroplating the fourth hard layer 470 on the conductive layer 420, the fourth hard layer 470 can provide additional mechanical support and protection for the conductive layer 420, and improve the deformation resistance.
[0125] In the fifth feasible implementation mode of the utility model, the designer can adjust the specific material and thickness size of the adhesion layer 410 according to the use requirement, which is not specifically limited here.
[0126] In a feasible embodiment, the material of the adhesion layer 410 is Ti, and the thickness of the adhesion layer 410 is less than or equal to 0.2 um. Preferably, the thickness of the adhesion layer 410 is 0.1 um.
[0127] In the fifth feasible implementation mode of the utility model, the designer can adjust the specific material and thickness size of the seed layer 460 according to the use requirement, which is not specifically limited here. In a feasible embodiment, the material of the seed layer 460 is Cu, and the thickness of the seed layer 460 is 0.2 um to 0.4 um.
[0128] By selecting Cu as the material of the seed layer 460 and controlling its thickness in the range of 0.2 um to 0.4 um, the conductive performance of the seed layer 460 and the interface bonding force between the seed layer 460 and the adhesion layer 410 can be effectively improved, which provides excellent substrate conditions for the subsequent electroplating process, thereby significantly enhancing the adhesion and uniformity of the conductive layer 420, reducing the interface contact resistance, and optimizing the current conduction efficiency.
[0129] In the fifth feasible implementation manner of the utility model, the designer can adjust the specific material and thickness size of the conductive layer 420 according to the use requirement, which is not specifically limited here. In a feasible embodiment, the material of the conductive layer 420 is Cu, and the thickness of the conductive layer 420 is greater than or equal to 1.5 um.
[0130] The designer can adjust the specific material of the fourth hard layer 470 according to the use requirement, which is not specifically limited here. In a feasible embodiment, the material of the fourth hard layer 470 is Ni. In another feasible embodiment, the material of the fourth hard layer 470 is NiAu.
[0131] In the fifth feasible implementation manner of the utility model, the designer can adjust the specific thickness size of the fourth hard layer 470 according to the use requirement, which is not specifically limited here. Preferably, the thickness of the fourth hard layer 470 is greater than or equal to 0.1 um.
[0132] In the embodiment of the utility model, the designer can adjust the area size of the first interconnection layer 110 according to the use requirement, which is not specifically limited here. In a feasible embodiment, the area of the first interconnection layer 110 is 8000 um 2 to 50000 um 2 .
[0133] By controlling the area of the first interconnection layer 110 in the range of 8000 um² to 50000 um², it is helpful to optimize the overall space layout and integration density of the binding structure while ensuring sufficient current conduction capability.
[0134] In the embodiment of the utility model, the designer can adjust the area ratio of the first interconnection layer 110 and the window structure 310 according to the use requirement, which is not specifically limited here. In a feasible embodiment, the area ratio of the first interconnection layer 110 and the window structure 310 is 1.05 to 1.2.
[0135] By controlling the area ratio of the first interconnection layer 110 and the window structure 310 in the range of 1.05 to 1.2, it is ensured that the structural stability of the first interconnection layer 110, and the bump area can meet the mechanical strength and process requirements, thereby optimizing the electrical connection performance and signal transmission efficiency.
[0136] In the embodiment of the utility model, the designer can adjust the specific structure of the first interconnection layer 110 according to the use requirement, which is not specifically limited here.
[0137] In a feasible embodiment, the first interconnection layer 110 is structured as a rectangle, the width of the first interconnection layer 110 is greater than or equal to 0.04 um, and the length of the first interconnection layer 110 is greater than or equal to 0.2 um.
[0138] By setting the first interconnection layer 110 as a rectangular structure and further limiting its size range, the current distribution uniformity of the bonding area can be effectively optimized, thereby significantly improving the reliability and service life of the bonding structure.
[0139] Moreover, by limiting the size range of the first interconnection layer 110, the electrical conduction performance and mechanical stability are taken into account while meeting the integration requirements, which helps to reduce the contact resistance and improve the signal transmission efficiency. In addition, the geometric characteristics of the rectangular structure are well compatible with the standardized process, which is conducive to reducing the manufacturing difficulty and improving the manufacturing efficiency.
[0140] In the embodiments of the present application, the designer can set the specific structure of the window structure 310 according to the requirements of the chip on current carrying capacity and impedance, which is not specifically limited here.
[0141] In a feasible embodiment, the window structure 310 includes a first windowing 311 which is proportionally reduced relative to the first interconnection layer 110. In a first specific embodiment, as shown in the embodiment shown in Figure 6 When the first interconnection layer 110 is rectangular, the first windowing 311 is a proportionally reduced rectangle.
[0142] In another feasible embodiment, the window structure 310 includes a plurality of second windowings 312 arranged at intervals. By arranging a plurality of second windowings 312, not only the layout flexibility and integration density of the bump area are improved, but also the heat dissipation performance and signal transmission efficiency are effectively improved, thereby enhancing the reliability and performance stability of the bonding structure.
[0143] In a second specific embodiment, as shown in the embodiment shown in Figure 7 The plurality of second windowings 312 can be arranged in a single column.
[0144] In a third specific embodiment, as shown in the embodiment shown in Figure 8 The plurality of second windowings 312 can be arranged in multiple columns. The multiple column arrangement is a multiple column parallel arrangement.
[0145] In a fourth specific embodiment, as shown in the embodiment shown in Figure 9 The plurality of second windowings 312 can be arranged in multiple columns. The multiple column arrangement is a multiple column staggered arrangement.
[0146] In the embodiments of the present application, the designer can adjust the specific shape of the second windowing 312 according to the use requirements, which is not specifically limited here.
[0147] In a feasible embodiment, the projection shape of the second windowing 312 in the thickness direction of the first interconnection layer 110 is circular, and the diameter of the second windowing 312 is greater than or equal to 25 um.
[0148] By making the diameter of the second window 312 be greater than or equal to 25 um, the current carrying capacity and thermal stability of the second window 312 region are effectively improved while meeting the requirements of precision machining and alignment tolerance, and the electrical performance and long-term reliability are further optimized.
[0149] In another possible embodiment, a projection shape of the second window 312 in a thickness direction of the first interconnection layer 110 is a regular polygon, and a circumscribed circle diameter of the second window 312 is greater than or equal to 25 um. For example, the circumscribed circle diameter of the second window 312 can be set to 30 um. The regular polygon can be a hexagon or an octagon, which is not specifically limited herein.
[0150] By making the circumscribed circle diameter of the second window 312 be greater than or equal to 25 um, the current carrying capacity and thermal stability of the second window 312 region are effectively improved while meeting the requirements of precision machining and alignment tolerance, and the electrical performance and long-term reliability are further optimized.
[0151] In the embodiment of the present application, the designer can adjust the minimum interval S between the window structure 310 and the edge of the first interconnection layer 110 according to the use requirement, which is not specifically limited herein. In a possible embodiment, the minimum interval S between the window structure 310 and the edge of the first interconnection layer 110 is greater than or equal to 4 um.
[0152] Embodiment two
[0153] The embodiment of the present application further discloses an ultrasonic fingerprint identification module, which comprises the binding structure as described in the embodiment one. The structure and effects of the binding structure are the same as those described in the embodiment one, which is not repeated here.
[0154] The designer can adjust the specific structure of the ultrasonic fingerprint identification module according to the use requirement, which is not specifically limited herein. The ultrasonic fingerprint identification module in the present application can comprise various ultrasonic fingerprint identification modules, for example, without limitation to a silicon substrate or a TFT substrate, without limitation to a piezoelectric material type, for example, polyvinylidene fluoride (PVDF) or polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE), PZT, BaTiO3, AlN and the like.
[0155] Embodiment three
[0156] The embodiment of the present application further discloses an electronic device, which comprises the ultrasonic fingerprint identification module as described in the embodiment two.
[0157] The structure and effect of the ultrasonic fingerprint identification module are the same as those in the second embodiment, and will not be repeated here. The electronic device includes but is not limited to a mobile terminal device, such as a mobile phone, a notebook computer, a tablet computer, and the like.
[0158] In the embodiment of the present application, the electronic device includes a screen, and the ultrasonic fingerprint identification module is arranged below the screen to identify the fingerprint of a finger pressed on the display screen.
[0159] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of to describe combinations shall include the elements, ingredients, components or steps identified, and such other elements ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the term "comprising" or "including" to describe combinations of elements, ingredients, components or steps herein also is taken to mean that other elements, ingredients, components or steps can be present in addition to those specifically recited, in order to achieve the stated purpose. The term "may" is intended to mean "possibly" in describing any attribute, parameter, circumstance or condition that can exist in connection with an attribute, parameter, circumstance or condition that is recited. Multiple instances of an element, ingredient, component or step can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step can be divided into multiple instances of an element, ingredient, component or step. The disclosure of alternatives for elements, ingredients, components or steps is not meant to be exhaustive or limiting. Many modifications and variations of the present application are possible in light of this disclosure without departing from the scope or spirit of the present application.
[0160] Each of the embodiments in the present specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be understood by referring to each other. The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.
Claims
1. A binding structure, characterized by, The application relates to a binding structure. The binding structure comprises: a silicon substrate layer, wherein a first interconnection layer is arranged on the silicon substrate layer; a flexible circuit board, wherein a second interconnection layer is arranged on the flexible circuit board; a passivation layer, wherein the passivation layer is arranged on the silicon substrate layer and covers the first interconnection layer, and a window structure is arranged on the passivation layer; 2. The binding structure of claim 1, wherein, a conductive structure, wherein the conductive structure comprises an adhesive layer and a conductive layer, at least part of the adhesive layer is arranged on the first interconnection layer in the window structure, and the conductive layer is arranged on the adhesive layer and is used for electrically connecting the second interconnection layer.
3. The binding structure of claim 2, wherein, The first interconnection layer comprises a metal pad arranged on the silicon substrate layer.
4. The binding structure of claim 1, wherein, The metal pad is an aluminum pad.
5. The binding structure of claim 1, wherein, The second interconnection layer comprises an ACF layer arranged on the flexible circuit board.
6. The binding structure of claim 5, wherein, The conductive structure comprises an evaporation-formed adhesive layer and an evaporation-formed conductive layer on the adhesive layer, and the conductive layer is electrically connected to the second interconnection layer.
7. The binding structure of claim 5, wherein, The material of the adhesive layer is Ti, and the thickness of the adhesive layer is less than or equal to 0.2 um.
8. The binding structure of claim 7, wherein, The thickness of the conductive layer is greater than or equal to 0.1 um.
9. The binding structure of claim 8, wherein, The conductive structure further comprises a first hard layer evaporation-formed on the conductive layer, and the first hard layer is electrically connected to the second interconnection layer.
10. The binding structure of claim 5, wherein, The thickness of the first hard layer is greater than or equal to 0.1 um.
11. The binding structure of claim 10, wherein, The conductive structure further comprises a second hard layer evaporation-formed on the adhesive layer, and the conductive layer is evaporation-formed on the second hard layer.
12. The binding structure of claim 1, wherein, The thickness of the second hard layer is 0.1 um to 0.2 um.
13. The binding structure of claim 12, wherein, The conductive structure comprises a sputtering-formed adhesive layer, a seed layer sputtering-formed on the adhesive layer and the conductive layer electroplated on the seed layer, and the conductive layer is electrically connected to the second interconnection layer.
14. The binding structure of claim 1, wherein, The material of the seed layer is TiW, and the thickness of the seed layer is less than or equal to 0.5 um.
15. The binding structure of claim 14, wherein, The conductive structure comprises a sputtering-formed adhesive layer, a seed layer sputtering-formed on the adhesive layer, the conductive layer electroplated on the seed layer and a fourth hard layer electroplated on the conductive layer, and the fourth hard layer is electrically connected to the second interconnection layer.
16. The binding structure of claim 2, wherein, The material of the seed layer is Cu, and the thickness of the seed layer is 0.2 um to 0.4 um.
17. The binding structure of claim 2, wherein, The area ratio of the first interconnection layer to the window structure is 1.05 to 1.
2.
18. The binding structure of claim 2, wherein, The window structure comprises a first window arranged in a proportionally reduced manner relative to the first interconnection layer.
19. The binding structure of claim 18, wherein, The window structure comprises a plurality of second windows arranged at intervals.
20. The binding structure of claim 18, wherein, The projection shape of the second window in the thickness direction of the first interconnection layer is a circle, and the diameter of the second window is greater than or equal to 25 um; or the projection shape of the second window in the thickness direction of the first interconnection layer is a regular polygon, and the diameter of the circumscribed circle of the second window is greater than or equal to 25 um.
21. An ultrasonic fingerprint identification module, comprising: The minimum interval of the window structure and the edge of the first interconnection layer is greater than or equal to 4 um.
22. An electronic device, comprising: The application further relates to a binding structure comprising any one of the binding structures as claimed in claims 1 to 20. The application further relates to an ultrasonic fingerprint identification module comprising the ultrasonic fingerprint identification module as claimed in claim 21.